Machine for the production of arcwelding electrodes



Spil3f1940l J. ALDER ET AL 2,213,431

MACHINE FOR THE PRODUCTION OF ARC-WELDING ELECTRODES Filed April 4, 1938 IIIIII'IIIIIIIIIII;:=::

INVENTOR8 JEAN ALDER Am/s G/a/z W 1* A TTOR NE Y6 Patented Sept. 3, 1940 UNITED STATES PATENT OFFICE MACHINE FOR THE PRODUCTION OF ARC- WELDING ELECTRODES Jean Alder and Alois Grilz, Zurich, Switzerland Application April 4, 1938, Serial No. 200,042 In Switzerland April 9, 1937 7 Claims. (Cl. 18'13) The manufacture of arc-welding electrodes the travelling electrodes as caused by the presmaygenerally be divided into two classes: the sure of the enveloping material, and thus assurimmersion method and the consolidation or coming the production of an absolutely uniform and pression method. In the former the bare rods centric electrode jacket.

or wires-are immersed into a liquid bath of coat- Another characteristic point of the present ining or enveloping material, taken out of the vention is the possibility of accurately adjusting bath and dried. This method of manufacture the ratio of electrode advance and volume of possesses the disadvantage that the enveloping enveloping material to be deposited. material upon liftingthe electrode out of the The machine for the realization of the advan- 10 bath dissociates, since the various constituent tages cited possesses a centering device in the 10 elements of the latter, in accordance with their press cylinders, isolated from the enveloping specific gravities, drop on" quicker or slower. A material and mounted upon an inclined plane, uniform and homogeneous composition of the in combination with tapered rollers. This cenenveloping mass, which is absolutely indispensatering device guides: the rod or wire to within ble for building up a uniform welding seam, a short distance from the discharge nozzle, centherefore cannot be obtained by means of the ters the wire and lets pass through any points immersion method. or portions of the latter which are of a difierent The thickness of the electrode envelope made gauge or diameter, still, however, maintaining according to the latter method also is not uniits centering action. Both cylinder and piston form. The welding wire nearly always is disare pierced by a guide tube, the core of which is 20 posed eocentrically within the envelope, thus adapted to the wire gauge in question. In order causing an unequal degree of flux of the electrode to overcome any resistances arising during the per unit of time. Since the fusing of the enpassage of the wire, especially those due to gauge velope, however, serves for neutralizing the arc, variations, a wire transporting device is provided :5 alloying the bath of fusion and ameliorating the within the press pistons which is adapted so as welding seam by preventing too rapid a cooling, to cling tothe electrode core with a force directly it is absolutely essential to eliminate the variaproportional to the degree of resistance met.

tions of the homogeneity, eccentricity and thick- In order to obtain always a uniform thickness ness of envelope unavoidable in the case of imof envelope, i. e. an accurate setting of the cormersion type electrodes. rect ratio of enveloping material and electrode 30 Apart from the immersion method various feed, a stepless regulating gearing is provided, pressing or consolidating processes, essentially which permits of a regulation of the core wire working on the principle of the hose presses, are feed independent of the piston advance. Finally, known to the art, by means of which it is sought and for the purpose of keeping the machine 5 to eliminate the disadvantages cited. It is to be ready for operation at all times, two cylinders said,'however, that these latter processes fail to are provided for, one of which is being filled, positively guarantee absolutely concentric elecwhile the other is in operation. trodes. The present invention is illustrated, by way In all pressing methods it is essential to build of example, in the accompanying drawing, in

up the electrode envelope of materials with such which 40 a low plasticity that the constituent elements do Fig. l is a schematic view of the machine, not dissociate neither during the manufacture of partly in section; the electrode nor during the preparation of the Fig. 2 is a longitudinal sectional view of the coating material. Only in this way is one able centering device;

,5 to attain an absolutely homogeneous and uniform Fig. 2a. is a vertical section taken approxienveloping structure for the electrode. mately through the center of the centering de- The present invention relates to improvements vice shown in Fig. 2; in machines for the production of electrodes of Fig. 3 shows a modified form of the centering the consolidation type from materials of 10W mechanism; plasticity, thus guaranteeing absolutely centric Fig. 3a is an end view of the device shown in 50 and homogeneous electrodes. Fig. 3 and According to the present invention, the elec- Fig. 4 shows diagrammatically the wire feedtrode cores are guided by tapered rollers extending mechanism. ing up to a short distance from the discharge The piston 2 moves within the cylinder l and nozzle, thus preventing a change of direction of is actuated by the spindles I which are driven by 55 the motor Ill. The centering device 4, from which an electrode 5 issues, is housed in the cylinder l. The guide tube 3 passes through the cylinder and piston. The wire feeding or transporting device 8 is driven by a stepless regulating gearing 9 over bevel gears.

The centering device according to Fig. 2 comprises the tapered rollers 13 confined within a cage. The said rollers I3 pass along with the wire as soon as a thickened portion of the wire is drawn up and thus give more room by sliding upon the conical surface It. At the same time, however, the spring [5 iscompressed, and the tapered rollers 13 are consequently returned into their starting or initial position as soon as the said thickened portion of wirehas' passed by.

The second form of centering device (Fig. 3)

comprises a slender metal cone 22, housed in the casing 4 and in which three radially. disposed leaves 23 slide in a longitudinal direction. The leaves 23 are radiallyguided by two discs 24 and 25, their ends sliding in a rectangular slot of the latter. The leaves 23, furthermore, are tapered on the outside, and are always pushed down into the cone 22 by means of a spring 26 and three axially disposed guide screws 21. Finally, a spring 28'is embedded'between the said guide leaves 23, which prevents the latter from falling together when guiding the wire horizontally after the electrode wire '5 has been withdrawn.

As in the first form of the centering device (Fig. 2), the form according to Fig. 3 also provides for the passage of any thickened portion of wire by displacing the leaves 23 in the direction of the advancing wire, meanwhile fully maintaining the centering action. The said leaves 23 slide, as shown, within the cone 22. If, now, the leaves become displaced in the direction of the advancing wire, they give more room. free. The spring 26 now is compressed. As soon as the thickened portion of wire has passed by, however, the spring 26 again returns the leaves 23 into their normal position. I

The wire transporting device 8, shown in Fig. 4,

' is driven by the bevel gears I8. The further transmission of power takes place by way of the pinions l1 andl9.' A fiutedroller 20 is mounted on the pinion I9 which transports the electrode core or wire'proper. -'As seen from Fig. 4, the transporting device comprisestwo identical parts engaging the electrode core from two sides. Since the sense of rotation of these two parts is opposed, the device upon meeting with a resistance rotates about the axle 2! and clings to the electrode 5 with a force corresponding to the said resistance.

As shown in Fig. 1, two cylinders l are provided,;which may be swung about the axle 6.

While one of these cylinders is in the operative position, the other may be filled with the envelopingmaterial. This filling operation is done by means of a piston moved by a handwheel H and a rack l2.

The machine, briefly, operates as follows: The wire transporting device 8 feeds an electrode wire into the guide "tube 3 which passes through the cylinder and piston, and then passes it'alongintothe centering device. At the point where the electrode leaves the latter, i. e. immediately'back of thedischarge nozzle, the enveloping material in the cylinder l approaches the electrode vs'rire and starts to envelop the latter.

. cylinder and disposed about the axis of the wire to be fed and mounted with an element in parallelism with said axis, means presenting inclined surfaces upon which the said rollers are mounted, and means for separating the contents of the cylinder from the rollers; the wire feeding device comprising a plurality of pinions and bevelled gears, and a fluted roller mounted on one of the said pinions; said tapered rollers being displaced on the inclined plane when a Wire portion of enlarged diameter passes through the centering device and acting to confine the wire in centered position with respect to the axis of the nozzle.

2. In an electrode enveloping machine of the character described, a press cylinder containing a wire centering device comprising a hardened cone in which three radially guided leaves are disposed, means for guiding said leaves for radial movement, whereby said leaves are separable at their inner edges for variable distances, and spring-pressed mechanism acting to urge the leaves into the cone and thereby cause said inner edges to engage and guide an electrode wire or rod being fed through the cylinder.

3. A machine according to claim 1, including a guide tube passing through the press cylinder and its piston.

4. A machine according to claim 1, wherein the wire transporting device is mounted and movable with the piston, the driving rolls of said device being yieldingly mounted in such manner that upon meeting with resistance during the advance of the wire they engage the wire with greater force.

5. A machine according to claim 1, wherein the bevel gears are in the form of friction gears which are adjustable to control the core wire speed independently of the piston advance.

6. A machine according to claim 1, wherein two press cylinders are provided, said cylinders being movable to bring one into the operating position while the other is brought to position for filling with the electrode-enveloping material.

7. An electrode enveloping machine comprising a press cylinder containing a wire centering device, a piston cooperating with the cylinder and a wire feeding device arranged to feed a wire to be coated into the wire centering device, said wire centering device including a plurality of tapered members arranged about the axis of the wire to be fed through the device and having a surface arranged in parallelism with said axis, resilient means urging said tapered members in unison toward the wire to center the same and supporting means for said members having inclined surfaces contacted by inclined surfaces of the tapered members to enable said members to move in unison away from the said axis when a thickened portion of the wire passes through the centering device.

JEAN ALDER. ALOIS GRILZ. 

